Hpertension is a complex genetic trait which is thought to involve the simultaneous presence of mutations in multiple genes. The identification of genes involved in hypertension will aid in the understanding of hypertension pathophysiology, allow for the presymptomatic diagnosis of high risk individuals, and potentially lead to novel forms of treatments. The major goal of this Hypertension SCOR is to use molecular methods to identify genetic loci contributing to this complex disorder. The most useful methods available for genetic dissection of complex diseases include nonparametric allele-sharing analysis of related affected human subjects (sib-pair and affected pedigree member analysis), and genetic analysis of animal models. Projects utilizing these methods are a major part of this Hypertension SCOR. This project will contribute to the identification of loci involved in hypertension by providing the necessary molecular resources for projects 1, 2 and 4. Specifically, we will use state-of-the-art methods to provide high throughput genotyping for both human and rat studies. In addition, we will contribute to the construction of a dense genetic map of the rat genome, by developing a minimum of 1000 high quality short tandem repeat polymorphic markers (STRPs). These markers will be made available to the scientific community, thus facilitating the study of rat models of hypertension in this and other Hypertension SCORs.